fs: Provide _remove_dir_contents

This splits remove_dir_all into two: one part is the thin wrapper for
_delete_dir_contents, and the other part is responsible for deleting
the top-level directory.

We are going to expose a function for only deleting the contents, and
this will be its primary building block.

I provided two entrypoints, one of which wraps the other, rather than
a boolean and a conditional, because IMO it mekes the code clearer.
(It would also have been possible to duplicate the canonicalize call,
but I felt that was worse.)

There is no functional change yet.

Signed-off-by: Ian Jackson <[email protected]>

Author: ijackson

src/fs.rs

@@ -60,8 +60,8 @@ pub fn remove_dir_all<P: AsRef<Path>>(path: P) -> io::Result<()> {
     // To handle files with names like `CON` and `morse .. .`,  and when a
     // directory structure is so deep it needs long path names the path is first
     // converted to the Win32 file namespace by calling `canonicalize()`.
-    let path = path.as_ref().canonicalize()?;
-    _delete_dir_contents(&path)?;
+
+    let path = _remove_dir_contents(path)?;
     let metadata = path.metadata()?;
     if metadata.permissions().readonly() {
         delete_readonly(metadata, &path)?;
@@ -76,6 +76,13 @@ pub fn remove_dir_all<P: AsRef<Path>>(path: P) -> io::Result<()> {
     Ok(())
 }
 
+/// Returns the canonicalised path, for one of caller's convenience.
+pub fn _remove_dir_contents<P: AsRef<Path>>(path: P) -> io::Result<PathBuf> {
+    let path = path.as_ref().canonicalize()?;
+    _delete_dir_contents(&path)?;
+    Ok(path)
+}
+
 fn _delete_dir_contents(path: &PathBuf) -> io::Result<()> {
     log::trace!("scanning {}", &path.display());
     let iter = path.read_dir()?.par_bridge();